Greasy Fork

JS FLACMetadataEditor

Allows you to edit metadata of FLAC files. CO

目前为 2018-04-12 提交的版本。查看 最新版本

此脚本不应直接安装,它是一个供其他脚本使用的外部库。如果您需要使用该库,请在脚本元属性加入:// @require https://update.greasyfork.cloud/scripts/40545/264746/JS%20FLACMetadataEditor.js

// ==UserScript==
// @description Allows you to edit metadata of FLAC files. CO
// @name        JS FLACMetadataEditor
// @namespace   universe.earth.www.ahohnmyc
// @version     0.0.1
// @license     GPL-3.0-or-later
// @grant       none
// ==/UserScript==

class VorbisComment extends Array {}

class VorbisCommentPacket {
    /* Need to easy initialization */
    _addComment(field) {
        let value = field.split('=')[1];
        field = field.split('=')[0].toUpperCase();
        if (!this.hasOwnProperty(field))
            this[field] = new VorbisComment();
        if (!this[field].some(storedValue=> storedValue===value))
            this[field].push(value.toString());
        return this;
    }
    toStringArray() {
        let array = [];
        Object.keys(this).sort().forEach(key=> {
            this[key].forEach(value=> {
                array.push(key+'='+value);
            });
        });
        return array;
    }
}

class FLACMetadataBlockData {}

class FLACMetadataBlock {
    constructor() {
        this.blockType = '';
        this.blockTypeNubmer = 0;
        this.blockSize = 0;
        this.data = new FLACMetadataBlockData();
        this.offset = 0;
    }
    get serializedSize() {
        switch (this.blockType) {
            case 'STREAMINFO': return 34;
            case 'PADDING': return this.blockSize;
            case 'APPLICATION': return 4+this.data.applicationData.length;
            case 'SEEKTABLE': return this.data.points.length*18;
            case 'VORBIS_COMMENT':
                let totl = this.data.comments.toStringArray().reduce((sum, str)=>sum+4+str.toUTF8().length, 0);
                return 4+this.data.vendorString.length+4+ totl;
            case 'CUESHEET': return 0;
            case 'PICTURE': return 4+4+this.data.MIMEType.toUTF8().length+4+this.data.description.toUTF8().length+4+4+4+4+4+this.data.data.length;
        }
    }
}

class FLACMetadataBlocks extends Array {}

class FLACMetadata {
    constructor() {
        this.blocks = new FLACMetadataBlocks();
        this.framesOffset = 0;
        this.signature = '';
    }
}

class FLACMetadataEditor {
    constructor(buffer) {
        if (!buffer || typeof buffer !== 'object' || !('byteLength' in buffer)) {
            throw new Error('First argument should be an instance of ArrayBuffer or Buffer');
        }

        this.arrayBuffer = buffer;
        this.metadata = new FLACMetadata();

        String.prototype.toUTF8 = function(str = null) {
            return new TextEncoder().encode(str ? str : this);
        };

        this._parseMetadata();

        return this;
    }

    /* unpack */
    _getBytesAsNumber            (array, start=0, end=array.length-start) {return Array.from(array.subarray(start, start+end)).reduce     ((result, b)=>result=256*result+b, 0);}
    _getBytesAsNumberLittleEndian(array, start=0, end=array.length-start) {return Array.from(array.subarray(start, start+end)).reduceRight((result, b)=>result=256*result+b, 0);}
    _getBytesAsHexString (array, start=0, end=array.length-start) {return Array.from(array.subarray(start, start+end)).map(n=>(n>>4).toString(16)+(n&0xF).toString(16)).join('')}
    _getBytesAsUTF8String(array, start=0, end=array.length-start) {return new TextDecoder().decode(array.subarray(start, start+end));}
    _getBlockType(number){
        switch (number) {
            case 0: return 'STREAMINFO';
            case 1: return 'PADDING';
            case 2: return 'APPLICATION';
            case 3: return 'SEEKTABLE';
            case 4: return 'VORBIS_COMMENT';
            case 5: return 'CUESHEET';
            case 6: return 'PICTURE';
            case 127: return 'invalid, to avoid confusion with a frame sync code';
            default: return 'reserved';
        }
    }
    _getPictureType(typeNumber){
        const types = [
            'Other',
            '32x32 pixels \'file icon\' (PNG only)',
            'Other file icon',
            'Cover (front)',
            'Cover (back)',
            'Leaflet page',
            'Media (e.g. label side of CD)',
            'Lead artist/lead performer/soloist',
            'Artist/performer',
            'Conductor',
            'Band/Orchestra',
            'Composer',
            'Lyricist/text writer',
            'Recording Location',
            'During recording',
            'During performance',
            'Movie/video screen capture',
            'A bright coloured fish',
            'Illustration',
            'Band/artist logotype',
            'Publisher/Studio logotype'
        ];
        return typeNumber<types.length ? types[typeNumber] : 'reserved';
    }
    /* pack */
    _uint32ToUint8Array(uint32) {
        const eightBitMask = 0xff;
        return [
            (uint32 >>> 24) & eightBitMask,
            (uint32 >>> 16) & eightBitMask,
            (uint32 >>> 8) & eightBitMask,
            uint32 & eightBitMask,
        ];
    }
    _uint24ToUint8Array(uint32) {
        const eightBitMask = 0xff;
        return [
            (uint32 >>> 16) & eightBitMask,
            (uint32 >>> 8) & eightBitMask,
            uint32 & eightBitMask,
        ];
    }
    _uint16ToUint8Array(uint32) {
        const eightBitMask = 0xff;
        return [
            (uint32 >>> 8) & eightBitMask,
            uint32 & eightBitMask,
        ];
    }
    _hexStringToUint8Array(str) {
        return str.replace(/(\w\w)/g,'$1,').slice(0,-1).split(',').map(s=> (parseInt(s[0],16)<<4) + parseInt(s[1],16));
    }

    get _vorbisComment() {
        let block = this.metadata.blocks.find(block=>block.blockType==='VORBIS_COMMENT');
        if (block)
            return block.data;
    }

    addComment(field, value = null) {
        if (field) {
            if (!value) {
                value = field.split('=')[1];
                field = field.split('=')[0];
            }
            field = field.toUpperCase();
            if (!this._vorbisComment.comments.hasOwnProperty(field))
                this._vorbisComment.comments[field] = new VorbisComment();
            if (!this._vorbisComment.comments[field].find(storedValue=> storedValue===value))
                this._vorbisComment.comments[field].push(value.toString());
        }
        return this;
    }
    removeComment(field = null, value = null) {
        if (!field) {
            Object.keys(this._vorbisComment.comments).forEach(key=> delete this._vorbisComment.comments[key]);
        } else {
            field = field.toUpperCase();
            if (!value) {
                delete this._vorbisComment.comments[field];
            } else {
                value = value.toString();
                if (this.hasOwnProperty(field))
                    this._vorbisComment.comments[field] = this._vorbisComment.comments[field].filter(storedValue=> storedValue!==value);
            }
        }
        return this;
    }
    getComment(field) {
        return this._vorbisComment.comments[field.toUpperCase()];
    }

    addPicture(buffer, APICType, MIMEType, ) {
        if (!buffer || typeof buffer !== 'object' || !('byteLength' in buffer)) {
            throw new Error('First argument should be an instance of ArrayBuffer or Buffer');
        }

    }



    _serializeMetadataBlock(block) {
        let bytes = new Uint8Array(block.serializedSize);
        let data = block.data;
        let offset = 0;

        switch (block.blockType) {
            case 'STREAMINFO':
                bytes.set(this._uint16ToUint8Array(data.minBlockSize));
                offset += 2;
                bytes.set(this._uint16ToUint8Array(data.maxBlockSize), offset);
                offset += 2;
                bytes.set(this._uint24ToUint8Array(data.minFrameSize), offset);
                offset += 3;
                bytes.set(this._uint24ToUint8Array(data.maxFrameSize), offset);
                offset += 3;
                bytes.set(this._uint24ToUint8Array((data.sampleRate<<4) + (data.numberOfChannels-1<<1) + (data.bitsPerSample-1>>4)), offset);
                offset += 3;
                bytes[offset] = (((data.bitsPerSample-1&0xF)<<4) + (Math.trunc(data.totalSamples/Math.pow(2,32))&0xF));
                offset += 1;
                bytes.set(this._uint32ToUint8Array(data.totalSamples), offset);
                offset += 4;
                bytes.set(this._hexStringToUint8Array(data.rawMD5), offset);
                break;
            case 'PADDING':
                break;
            case 'APPLICATION':
                bytes.set(data.applicationID.toUTF8());
                offset += 4;
                bytes.set(data.applicationData, offset);
                break;
            case 'SEEKTABLE':
                data.points.forEach(point=> {
                    bytes.set(this._hexStringToUint8Array(point.sampleNumber), offset);
                    bytes.set(this._hexStringToUint8Array(point.offset), offset+8);
                    bytes.set(this._hexStringToUint8Array(point.numberOfSamples), offset+16);
                    offset += 18;
                });
                break;
            case 'VORBIS_COMMENT':
                    bytes.set(this._uint32ToUint8Array(data.vendorString.toUTF8().length).reverse(), offset);
                offset += 4;
                bytes.set(data.vendorString.toUTF8(), offset);
                offset += data.vendorString.toUTF8().length;

                let comments = data.comments.toStringArray();
                bytes.set(this._uint32ToUint8Array(comments.length).reverse(), offset);
                offset += 4;
                comments.forEach(comment=> {
                    bytes.set(this._uint32ToUint8Array(comment.toUTF8().length).reverse(), offset);
                    offset += 4;
                    bytes.set(comment.toUTF8(), offset);
                    offset += comment.toUTF8().length;
                });
                break;
            case 'CUESHEET':
                break;
            case 'PICTURE':
                bytes.set(this._uint32ToUint8Array(data.APICtype));
                offset += 4;
                bytes.set(this._uint32ToUint8Array(data.MIMEType.toUTF8().length), offset);
                offset += 4;
                bytes.set(data.MIMEType.toUTF8(), offset);
                offset += data.MIMEType.toUTF8().length;

                bytes.set(this._uint32ToUint8Array(data.description.toUTF8().length), offset);
                offset += 4;
                bytes.set(data.description.toUTF8(), offset);
                offset += data.description.toUTF8().length;

                bytes.set(this._uint32ToUint8Array(data.width), offset);
                offset += 4;
                bytes.set(this._uint32ToUint8Array(data.height), offset);
                offset += 4;
                bytes.set(this._uint32ToUint8Array(data.colorDepth), offset);
                offset += 4;
                bytes.set(this._uint32ToUint8Array(data.colorNumber), offset);
                offset += 4;
                bytes.set(this._uint32ToUint8Array(data.data.length), offset);
                offset += 4;
                bytes.set(data.data, offset);
                break;
        }
        return bytes;
    }

    serializeMetadata() {
        let newMetadataLengthFull = 4+this.metadata.blocks.reduce((sum, block)=>sum+4+block.serializedSize, 0);
        let newSize = newMetadataLengthFull + ((this.arrayBuffer.byteLength>this.metadata.framesOffset)? this.arrayBuffer.byteLength-this.metadata.framesOffset : 0);

        let bytes = new Uint8Array(newSize);
        bytes.set(this.metadata.signature.toUTF8());

        let offset = 4;
        let lastBlock = false;
        this.metadata.blocks.forEach((block, n, blocks)=>{
            if (blocks.length-1 === n) lastBlock = true;
            bytes[offset] = block.blockTypeNubmer | (lastBlock<<7);
            offset += 1;
            bytes.set(this._uint24ToUint8Array(block.serializedSize), offset);
            offset += 3;

            bytes.set(this._serializeMetadataBlock(block), offset);
            offset += block.serializedSize;
        });

        // console.info('old meta size: %d, new: %d, delta: %d', this.metadata.framesOffset, newMetadataLengthFull, Math.abs(this.metadata.framesOffset-newMetadataLengthFull) );
        // console.info('old size: %d, new: %d, delta: %d', this.arrayBuffer.byteLength, newSize, Math.abs(this.arrayBuffer.byteLength-newSize) );
        // console.info('frames size: %d, to copy: %d', this.arrayBuffer.byteLength-this.metadata.framesOffset, new Uint8Array(this.arrayBuffer).subarray(this.metadata.framesOffset).length);
        // console.info('offset: %d', offset );

        bytes.set(new Uint8Array(this.arrayBuffer).subarray(this.metadata.framesOffset), offset);

        this.arrayBuffer = bytes.buffer;
        return this;
    }


    _parseMetadataBlock(array, arrayOffset, type, size) {
        let blockData = array.subarray(arrayOffset, arrayOffset+size);
        let offset = 0;
        let data = new FLACMetadataBlockData();
        switch (type) {
            case 'STREAMINFO':
                data.minBlockSize = this._getBytesAsNumber(blockData, offset, 2);
                offset += 2;
                data.maxBlockSize = this._getBytesAsNumber(blockData, offset, 2);
                offset += 2;
                data.minFrameSize = this._getBytesAsNumber(blockData, offset, 3);
                offset += 3;
                data.maxFrameSize = this._getBytesAsNumber(blockData, offset, 3);
                offset += 3;
                data.sampleRate = this._getBytesAsNumber(blockData, offset, 3)>>4;
                offset += 2;
                data.numberOfChannels = 1+ ((blockData[offset]>>1) &7);
                data.bitsPerSample = 1+ ((1&blockData[offset]) <<4) + (blockData[offset+1]>>4);
                offset += 1;
                data.totalSamples = (blockData[offset]&0xF)*Math.pow(2,32) + this._getBytesAsNumber(blockData, offset+1, 4);
                offset += 5;
                data.rawMD5 = this._getBytesAsHexString(blockData, offset, 16).toUpperCase();
                break;
            case 'PADDING':
                break;
            case 'APPLICATION':
                data.applicationID = this._getBytesAsUTF8String(blockData, offset, 4);
                offset += 4;
                data.applicationData = blockData.subarray(offset);
                break;
            case 'SEEKTABLE':
                data.pointCount = size/18;
                data.points = [];
                for (let i=0; i<data.pointCount; i++) {
                    data.points.push({
                        sampleNumber: this._getBytesAsHexString(blockData, offset, 8),
                        offset: this._getBytesAsHexString(blockData, offset+8, 8),
                        numberOfSamples: this._getBytesAsHexString(blockData, offset+16, 2)
                    });
                    offset += 18;
                }
                break;
            case 'VORBIS_COMMENT':
                let vendorLength = this._getBytesAsNumberLittleEndian(blockData, offset, 4);
                offset += 4;
                data.vendorString = this._getBytesAsUTF8String(blockData, offset, vendorLength);
                offset += vendorLength;

                let userCommentListLength = this._getBytesAsNumberLittleEndian(blockData, offset, 4);
                offset += 4;
                data.comments = new VorbisCommentPacket();

                let commentLength = 0;
                for (let i=0; i<userCommentListLength; i++) {
                    commentLength = this._getBytesAsNumberLittleEndian(blockData, offset, 4);
                    offset += 4;
                    data.comments._addComment(this._getBytesAsUTF8String(blockData, offset, commentLength));
                    offset += commentLength;
                }
                break;
            case 'CUESHEET':
                break;
            case 'PICTURE':
                data.APICtype = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                let MIMELength = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                data.MIMEType = this._getBytesAsUTF8String(blockData, offset, MIMELength);
                offset += MIMELength;
                let descriptionLength = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                data.description = this._getBytesAsUTF8String(blockData, offset, descriptionLength);
                offset += descriptionLength;
                data.width = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                data.height = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                data.colorDepth = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                data.colorNumber = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                let binarySize = this._getBytesAsNumber(blockData, offset, 4);
                offset += 4;
                data.data = blockData.subarray(offset, offset+binarySize);
                break;
        }
        return data;
    }

    _parseMetadata() {
        let bytes = new Uint8Array(this.arrayBuffer);

        this.metadata.signature = this._getBytesAsUTF8String(bytes,0,4);

        let offset = 4;
        let lastBlock = false;
        let block;

        let iteration = 0;
        while (!lastBlock && offset < bytes.length) {
            if (iteration++ > 42) throw new RangeError('Too much METADATA_BLOCKS. Looks like file corrupted');

            block = new FLACMetadataBlock();

            block.offset = offset;
            lastBlock = !!(bytes[offset] >> 7);
            block.blockTypeNubmer = bytes[offset] & 127;
            block.blockType = this._getBlockType(block.blockTypeNubmer);
            offset += 1;
            block.blockSize = this._getBytesAsNumber(bytes, offset, 3);
            offset += 3;
            block.data = this._parseMetadataBlock(bytes, offset, block.blockType, block.blockSize);
            offset += block.blockSize;

            // if (block.blockType !== 'PADDING')
                this.metadata.blocks.push(block);
        }
        this.metadata.framesOffset = offset;
        return this;
    }
}